I bought mine when Tacx was not owned by Garmin. Check the Tacx website, I believe I registered mine there.
Either that or it was via the tacx app. You need the app to update the trainer anyways, so 2 birds with 1 stone.
Youâd obviously have to replace the floor mat though 
Haha I like to mix it up. Send me one and I will replace it 
Well update time after using for a few days. Was updated to current firmware and everything.
Going to send the Neo back as it still has virtual wheel slip on low gears even though it was supposed to be fixed on the 2T. Will keep going with my trusty old kickr snap and powermatch with my 4iiii left crank.
I think with the direction that most companies are going these days with the electro-magnetic resistance, âvirtual wheel slipâ is going to be difficult if not impossible to eliminate for any punchy riders.
I kinda wish I had known this in relation to the Neo Bike. Itâs not a dealbreaker by any means, but it is a minor annoyance. Not like the Wahoo bike would be any better.
True and makes sense as it is cool technology. It just annoys me and I had hopes the 2t eliminated it as people said it did but it did not for me anyway. Not all is lost though as I will go back to old faithful for a while longer.
Maybe its time to take that $$ and apply it to a mtn bike.
I wave a 25W spread between my vectors and Neo 2 The vector power numbers line up with calculated power required for the local big hill. The spread varies somewhat with power output but is fairly consistent at 25W. Both produce repeatable results. Any ideas or comments?
Well to follow up with this, Garmin ended up replacing my Neo 2 with a 2T. Put up my first workout with it tonight and its still really not matching up with the Faveroâs to my liking. Average is 7% higher on my Faveroâs vs the 2T. I did Dade -1 tonight and it turns the workout from mildly difficult to incredibly hard. I really donât want to fiddle with adjusting workout difficulties and such.
Maybe it is my pedals reading high, but Iâm inclined to trust the pedals. Some of my race performances really wouldnât make sense at an 8-10% reduction in power without an insanely good Cda according to Best Bike Split math. Plus the weighted calibration test on the pedals nailed the weight to within a few grams (<0.01%). Going to return the trainer to REI. Weâll see if they give me any hassle for trying to return a different product than the one I bought, even if it is 40% more money. 
@TravisM why arenât you using powermatch?
1 Like
I wanted to be able to leave my TT bike on the trainer and my Faveroâs on the road bike for outdoor riding without constantly swapping gear around.
You could set a lower FTP value in TR and this will compensate for the difference for you. Basically power test with the power source you are using. The absolute value doesnât really matter.
4 Likes
Probably, but for the $1,000 spent on this trainer Iâm really not happy with anything less than perfection. I donât even use Zwift, so I really donât need all the fancy features of this trainer. I bought it because both GPlama and DCrainmakerâs reviews showed it tracking extremely closely to their pedal based power meters. Iâll just go back to my Road machine for now.
Just throwing this out there but how do you know your pedals are accurate? How do you know what your âactual power isâ without a calibration tool? Unless you are DC Rainmaker with like 6 power meters and you can test between many sources what is accurate, it really is unknown. Even then, its all relative. Unless you can calibrate the power yourself and verify (and that is with an experimental setup) IMO itâs just an inherent issue with reading power; you will always have some offsets but the important thing is low variations between readings. High accuracy could mean âabsolute accuracyâ of the reading, or âhow accurate the measurements areâ.
You should really use power match to have one source of power or test to see what the difference between the 2 power meters are and understand the offset. I am more concerned about paying for low variations than have huge variations but a âcorrect average powerâ. The former can make you faster, but the latter will just be excessive noise.
4 Likes
Just throwing this out there as well but the Tacx would read similar to a hub based power meter, where drivetrain losses are not captured and what you read is the âtransferredâ power that the ground would feel. OTOH in crank or pedal power based sensors, drive train losses are included in the power that is read, so unless theres software to account for this (it is from my understanding that it is NOT accounted for) you would have a non-negligible source of error. Unless you have a friction-less chain/drivetrain setup⌠the power readings will inherently have an offset. I spoke to some experts the other day on this and they confirmed that hub based power meters are the âgold standardâ they would use to âuse for their dataâ. However, even with an offset, if the readings are accurate with respect to low variances, it doesnât matter⌠unless you want to compare dick sizes, in which case you would need the exact same setup, or⌠get the most highly offset reading you can get, which will ensure you maximize your readings.
3 Likes
Well one thing that seems telling to me, is that the Neo 2 was pretty wildly 8-15% lower than the Faveroâs, but now the Neo 2T is a much more consistent 7-9% lower than the Faveroâs, so even TacX is having software issues deciding how to calculate power. Like I said above, I bought this because in GPLama and DCrainmakerâs results, it was tracking very close to pedal based power meters and for me, I bought it with the sole intention of not needing Power Match so I wouldnât have to move gear around and carry bikes up to my second floor where my trainer room is. So in my case, its not worth $1,000 to me if I end up needing to use the Faveroâs for Power Match anyways.
And as far as actual accuracy concerns go, I did the static weight test on my Faveroâs twice and both times it was able to measure an 8kg weight to within <5 grams, so the strain gauges in the pedals are working nominally. Any power issues coming from the pedal at that point should be from Faveroâs software calculations and from the results Iâve seen across the review board, I have no reason to doubt them.
Iâm not trying to go out and say that the TacX is wrong. I definitely donât have enough information to say that, but I just wanted to provide an additional data point for someone looking to buy it, since the two major reviewers people are looking at show different data. YMMV, but in the end it wasnât worth my $1,000.
1 Like
Again, I am not in the realm of being an expert on this topic, but you canât determine if the power meter is 100% accurate unless you actually tested the entire system in an experimental setup with a known input wattage/force and saw what kind of response you get. Not to say the Neo or the Faveroâs are right or wrong, but it is extremely difficult to say which is which in this case where you have 2 ârelatively vettedâ data sets that seem off. Note that even crank based power meters have issues, as seen in things such as the new Shimano cranks. Depending on where you place the strain gauge, it will have different characteristics due to material properties (shape, asymmetry etc.)
Again, if you know the offset, just input the offset and be done with it. Again, data accuracy should be very good. Only caveat is I have heard the Neo does have some lower readings when at high flywheel speeds, as there is no strain gauge in the unit, so if you are using ERG its best to use an easy gear and let the device determine the power for you.
And lastly something to consider, manufactures errors may come into play as well. Lets say both power meter manufacturers say they have a 1% error range. I am not sure if this is an error with respect to your âabsolute wattageâ or your âwattage readingsâ (ie readings are +/- 1% vs you are 1 watt high or low for an absolute 100 watt value, if both it would be reading 101 x 1.01 or 101 x .99 or 99 x 1.01 or 99 x.99 watts). Drivetrain losses are non-negligible (note quick google :Mechanical Resistance on Bikes: Drivetrain Efficiency & Hub Bearings â Ride Far) so lets estimate 5-7% drive train losses (and worst case you cross chain so lets just say its 7.5%) so now your readings are 7.5% off empirically, even before you consider the device manufacturer acceptable errors. Note this is a napkin calculation.
So now your 100 watts absolute at the pedal will read 92.5 watts absolute at the hub. Note that with errors lets say the pedals read high, will read 101 x 1.01 watts while the neo will read low: (92.5-92.5*.01) x 99 watts (worst case, note we assume the offset error is reading 1% off the absolute value and factoring in a 99% accuracy of the meter, both within tolerance) and we now have your pedal reading 102 watts and your hub reading 90.659 (90.7 lets say). Whats the difference between the 2?
I get 11%. 11% difference. All within known qualities about the 2 power meters. I have no idea if the power meter manufacturers and/or smart trainer manufacturers have some secret sauce to lower the differences, but I would be suspect of that. Do you wax your chain? How good do you clean it? What brand of chain do you use? Do you use high quality bearings? Is your chain sized correctly? Are you cross chaining? etc.etc.
Someone can prove me wrong and explain to me how or why my write up may or may not be the case. If anything this emphasizes how you should use one power source, or understand that offset is offset. Of course this is worst case, but it falls within the manufacturers specs and standards. Thats not to say either power meter or device has anything going wrong, seems like both may be perfectly fine and you are just seeing science being science. If they both read accurately with a measured offset, they are both functioning absolutely as expected.
Edit: Itâs worth noting that I believe power meter manufactures and smart trainers are typically 1.5-2% error range, so this will magnify the difference you would read between the 2 meters. End of the day, as long as both power source are accurately recording and the only issue is the offset, there is nothing wrong with the power meters. Throw an offset value and you are done.
3 Likes
Offset doesnât really work here either because thatâs adjusting an absolute number of watts. Iâm seeing a scaled difference between the two. If I put in an offset of 20 watts that worked at 200 watts, it would still be reading wrong 100 watts and 300 watts.
I could use the power scale on the Faveroâs to adjust everything down 10%, but honestly Iâve been training on them for 2 years now and know what wattage targets feel like pretty well, so I donât want to make that adjustment in my brain. Honestly if TacX had an option to scale power output from the reading I could probably make it work, but they donât have an ability to do that, probably because they want to get involved in E-Sports and allowing the user to just scale the power from the device wouldnât work with that goal.
Again I donât know what else to say other than either power meter could be wrong, you cant determine if its the pedals or the neo without an experimental setup. Maybe you are power smoothing?
Call me a stickler but I try not to get too invested in the numbers and as long as the device allows me to train with a somewhat targeted precision I do not care if its +/-2 to 4% or whatever, as raceday nerves already account for more than what your power meter will likely tell you. Maybe ask on DC Rainmakers review comment section and he would have a better explanation or guess as to what the issue might be. Otherwise I think you might be obsessing over the numbers a bit too much. But hey, if you are unhappy with the product return it! Itâs your hard earned cash
2 Likes
I have a 2T and a stages left side PM.
The 2T is on the lastest firmware and last night I did a TR workout using only the 2T and Bluetooth (no stages or powermatch). I captured the workout in Zwift as well on Ant+ on the stages. During the workout it appeared that the 2T was 10+w higher than the stages. Post workout I compared the data in TR and 1 minute power was within 2 or 3 watts.
I donât expect them have the same instantaneous readings because there is so much variation even within a single second. If they are .5sec out of phase with each other its reasonable to get different readings.
I was disappointed on the perceived 10w difference but a 2w difference on best 60 sec power in the workout is pretty good. I donât quite know how to react to that. I think the next step is to capture both in a single workout file and analyze it and see what that difference looks like.
Is it left side only that is being multiplied by 2? This in itself is another source of error, as you just power x 2 to get the âright side powerâ but as we all know, thats not the case (left vs right side power differences), not to mention that this amplifies errors.
But I have a left sided 4i power meter and I run into the same issues you just mentioned. I get different readings, which is to be expected.
Note that the mentioning of phase and such is also an interesting topic, as I am not sure how the frequency and recording is done from brand to brand. That would be more of a software question but I would not be surprised to see issues with respect to data recording like you mentioned. DC Rainmaker seems to have a better handle on this and he has a tool for comparing power profiles.
Ill be honest though, what do we have to gain by analyzing the numbers and being obsessed over the accuracy? I mean long term, it really has minimal impact and as long as you are aware of some fluctuations, I am sure that the differences would not significantly impact your training. If the reading is off by 2%, well thatâs still within many manufacturers errors. I seriously think from a performance standpoint, its a waste of time and energy to get so bogged down in the numbers when they really have no direct impact on your long term training. If you gave two identical people the 2 power meters and they never knew it was âoffâ they would likely be extremely similar come race day and any variations would likely be due to conditional or situational or race day effects.